There are four conventional ways for making a textured surface on a solar cell. In a chemical method, a chemical solution is used to etch a smooth surface of a semiconductor device into a textured surface. In a mechanical method, a machine is used to scratch a smooth surface of a semiconductor device into a textured surface. In a laser method, laser is used to cut a smooth surface of a semiconductor device into a textured surface. In an ion bombard method, ion beams are used to bombard a smooth surface of a semiconductor device into a textured surface.
Referring to FIGS. 6 to 8, in the chemical method, there is provided a P-type silicon chip 50 including a smooth front surface 50a and a smooth rear surface 50b. An HF solution or KOH solution is used to etch the smooth front surface 50a into a textured surface 50c to reduce the reflection of sunlit. A tubing furnace diffusion method, screen printing method, spin coating method or jet printing method is executed to dose N-type impurities such as phosphor or arsenic into the textured surface 50c of the P-type silicon chip 59, thus forming an N-type impurity diffusion region 51a. Finally, an evaporation method or chemical vapor deposition method is used to form an ARC 52 of titanium oxide, tantalum oxide or silicon nitride on the textured surface 50c of the P-type silicon chip 50. This chemical method is however long and expensive for having to forming the impurity diffusion region 51 and the ARC 52 after the forming of the textured surface 50c. Moreover, the efficiency of the conversion of solar energy into electricity with the resultant silicon solar cell is low.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.